Journal: Food Research International, vol. 78, p. 88–95, 2015
International Standard Numbers:
Open Access: none
Konjac glucomannan (KGM) is a soluble dietary fiber. It is a polysaccharide of the mannan family, obtained from the root tuber of the Amorphophallus konjac plant ( An, Thien, Dong, Dung and Du, 2010 and Chua, Baldwin, Hocking and Chan, 2010), which has been used in manufacturing food and consumed for over 1000 years in the East (Walsh, Yaghoubian, & Behforooz, 1984). Currently, in the markets of the Western world, various types of food products containing KGM are commercially available and glucomannan supplements are marketed in the form of capsules, pills or powders. In food, KGM is used as an additive with an emulsifying and thickening effect ( Iglesias-Otero, Borderías and Tovar, 2010 and Liu, Wang and Ding, 2013). Besides this use as a texture modifier, KGM is also used for its functional effect on health. In 2010, the European Food Safety Authority (EFSA, 2010) confirmed its positive effect on body weight reduction in the context of an energy-restricted diet. This functional effect is based on its capacity to absorb water in the gastric tract, swelling to produce satiety through stomach distension (Keithley & Swanson, 2005). Although one of the nutritionists' recommendations for overweight people is to consume fiber-rich food, not all fibers contribute to promoting and prolonging satiety, as this depends on their chemical structure and physicochemical properties ( Jebb, 2007 and Wanders, Van den Borne, De Graaf, Hulshof, Jonathan, Kriste, 2011). For this reason, due to its recognized effect, the present study focuses on KGM as a satiating agent.
When designing a new product with a functional component, the selection of the carrier or form of presentation is an important factor to take into account. It has been observed in a previous work (Krutulyte et al., 2011) that a good fit between carrier and ingredient has a positive influence on the market success of the product. Another factor to take into consideration is the package. It is well known that packaging plays an important role in communicating and attracting people and that it could influence the consumers' in-store decision-making process (Underwood & Klein, 2002). The front-of-package labeling normally includes images and verbal information, which are the first contact with the consumer (Carrillo, Fiszman, Lähteenmäki and Varela, 2014 and Carrillo, Varela and Fiszman, 2012). For this reason, it is worth studying what consumers understand or perceive from these images and information in the case of products containing or made of KGM.
For this purpose, techniques to gather consumer perception information are the best way to understand their attitudes and preferences (Ares, Deliza, Barreiro, Giménez, & Gámbaro, 2010). Word association has been shown to be a good tool for obtaining spontaneous information about consumer perceptions of different kinds of foods (Mitterer-Daltoé, Carrillo, Queiroz, Fiszman and Varela, 2012 and Roininen, Arvola and Lähteenmäki, 2006). Another useful technique is projective mapping, in which the consumers think of the product as a whole. The results show that this technique provides intuitive and less rational responses from consumers. It is also useful for revealing relationships between multiple products in a visual manner (Carrillo, Varela and Fiszman, 2012 and Nestrud and Lawless, 2010). The above two techniques involve the use of stimuli which can be verbal or visual. The participants project their subjective opinions or beliefs about the stimuli in the form of general, overall perceptions (Hofstede, Hoof, Walenberg, & Jong, 2007).
For analyzing specific attributes, other kinds of sensory tool are required. In the present study, the use of conjoint analysis (CA) made it possible to examine preferences for some specific factor (at several levels) quantitatively, and the contribution made by each. CA involves presenting consumers with some choices and identifying the best drivers of those choices